Ethyl formate as a methyl bromide alternative for phytosanitary disinfestation of imported banana in Korea with logistical considerations

Methyl bromide (MB) use for quarantine and phytosanitary purposes is being phased out. Several effective MB alternatives have been identified depending on the target system. Industry commitment for the shift to new technologies will depend not only on the efficacy of alternatives but also on their compatibility and integrability into existing operations. We compared the efficacy of MB and ethyl formate (EF) for disinfestation of Planococcus citri (Risso) (Hemiptera: Pseudococcidae) as a representative surface pest on banana and evaluated whether EF fumigation is compatible with the current packaging materials and loading ratio used by the South Korean banana import industry. Fumigation trials with P. citri adults and eggs showed that EF was at least as effective as MB at the EF and MB concentrations recommended under the current phytosanitary disinfestation guidelines. From a logistical standpoint, EF gas could not effectively penetrate plastic bagging typically used in banana cartons during commercial shipping. Also, EF sorption to bananas and packing materials (used as cushioning inside bagging) further lowered realized EF concentrations around bananas. These reductions in EF concentration translated into reduced mortality of P. citri eggs, indicating that despite similar efficacy of MB and EF for controlling P. citri, further consideration and optimization of other industry logistics such as packaging and loading ratio is necessary to enhance the adoption of this MB alternative.